The following description relates to determining a target net treating pressure for a subterranean region. The effective permeability of a subterranean rock formation can be increased by fracturing the rock. For example, hydraulic fracture treatments are often used to fracture shale, coal, and other types of rock formations. During a hydraulic fracture treatment, fluids are pumped into the formation (e.g., through a wellbore) under high pressure, and the pressure of the fluid in the formation fractures the rock.